kwt 14-3 rev1

KOBELCO Puts the Customer First with All-in-One Product and Service

Vol.14 No.3 2011

TODAYTODAY

KOBELCO WELDING TODAYPRODUCTS SPOTLIGHT

Vol. 14 No. 3 2011 1

DW-308L-XRDW-316L-XR

Helping Workplaces Comply withNew OSHA Standards by Reducing

Cr(VI) Emissions

In order to reduce a risk of significant health effects, the Occupational Safety and Health Administration (OSHA)

in the USA has amended the existing standard of the permissible exposure limit (PEL) of hexavalent chromium, also known as Cr(VI), from 52 to 5 µg/m3 effective from June 2010. This rugulation applies to all manufacturing processes where Cr(VI) is present. Under this rule, the welding industries are required to reduce occupational exposure to Cr(VI) to less than the new PEL, which may need safer materials and equipment depending on the workplace environment.

Taking into account this amended OSHA standard, Kobe Steel has developed two new f lux-cored wires (FCWs) for stainless steels, PREMIARCTM DW-308L-XR (AWS A5.22 E308LT0-1/-4) and PREMIARCTM DW-316L-XR (AWS A5.22 E316LT0-1/-4), both of which are now available.

Because f lux cored arc welding (FCAW) generates more welding fumes than other stainless steel welding methods, it presents a burdensome safety challenge. In ad-dition, the welding fumes emitted by stainless steel FCAW contain chromium oxide (Cr2O3) in a range of 10-20% as shown with an example in Figure 1, a part of which exists as highly toxic Cr(VI). This figure shows the typical com-position of fumes generated by a conventional 308L-type FCW. These fumes were collected following ISO 15011-1:2009, and the Cr(VI) in the fumes was analyzed accord-ing to ISO 16740:2005.

Others

Na2O+K2O

MnO

Cr2O3

SiO2

Fe2O330%

17%14%

13%

10%

16%

Figure 1: The typical chemical composition of welding fumes generated by a conventional 308L-type FCW.

As seen in Figures 2 and 3, the Cr(VI) emission rates of DW-308L-XR and DW-316L-XR are greatly reduced to 1/5 or 1/10 the amount emitted by conventional stainless steel FCWs (DW-308L and DW-316L).

The chemical compositions and mechanical properties of all weld metals deposited by DW-308L-XR and DW-316L-XR, shown in Table 1, are almost identical to those of the conventional FCWs for stainless steels.

600

500

400

300

200

100

0

−89%

−87%

42 62

DW-308LDW-308L-XR

375

475

100%CO2 75%Ar-25%CO2

Cr(

VI)

emis

sion

rate

(µg/

min

)

Figure 2: DW-308L-XR greatly reduces Cr(VI) emission rates in comparison with conventional DW-308L.

600

500

400

300

200

100

0

−80% −92%

9539

DW-316LDW-316L-XR

465483

100%CO2 75%Ar-25%CO2

Cr(

VI)

emis

sion

rate

(µg/

min

)

Figure 3: DW-316L-XR remarkably reduces Cr(VI) emission rates in comparison with conventional DW-316L.

Table 1: Chemical and mechanical properties of all weld met-als deposited by the XR series FCWs

Trade desig. DW-308L-XR DW-316L-XRShielding

gas 100%CO275%Ar-25%CO2

100%CO275%Ar-25%CO2

C (wt%) 0.026 0.027 0.020 0.025Si 0.66 0.74 0.67 0.74Mn 1.13 1.29 1.16 1.28P 0.016 0.016 0.016 0.016S 0.008 0.007 0.008 0.008Cu 0.015 0.016 0.025 0.025Ni 9.6 9.5 12.0 12.0Cr 18.8 19.4 18.5 18.9Mo 0.01 0.01 2.4 2.4FN*1 8 11 8 9

0.2%PS (MPa) 367 396 404 400TS (MPa) 550 583 542 548El (%) 44 40 36 42RA (%) 45 42 44 45

*1: FN is Ferrite Number by WRC-1992 diagram.

Although use of the XR series FCWs will substantially reduce exposure to Cr(VI) in the workplace, it is recom-mended to control exposure by using respiratory protec-tion, ventilation equipment and protective work clothing to achieve a safer workplace environment.

KOBELCO WELDING TODAY PREFACE

2Vol. 14 No. 3 2011

KOBELCO WELDING TODAYis published by

Marketing DepartmentWelding Business, Kobe Steel, Ltd.

URL: http//www.kobelco.co.jpEmail: [email protected]

Advanced welding processeswith dedicated wiresfor car manufacturing

TRUSTARCTM MM-1HS:an innovative metal-typeFCW for car production

KWI and KWMK:strategic bases for sales &marketing in India and Korea

A report from KWAI inthe exciting Space City ofHouston

Communicating more closely with customersin order to fulfill their needs for the best

welding products and total solutions

Dearest KWT readers! I am Shinichi Tanaka, and, since January 2011, the General Manager of the International Sales and Marketing Sec-

tion. I have now been involved in the overseas business for 19 years ― though not continuously ― including two postings overseas, one at Kobelco Welding of America Inc. for a year from 1990 and the other at Kobelco Welding of Europe B.V. in the Netherlands for 5 years from 1997.

Since October 2010, the domestic and overseas sales and marketing departments of Kobelco’s Welding Business have been united into one de-partment in order to improve internal communication, enhance the power of total welding solutions and strengthen global operations. In particular, we have focused our sales and marketing effort on three industries: ship-building and offshore/onshore oil drilling rig fabrication, automobile and construction machinery industries, and energy related plant fabrication.

Although the needs of these customers continue to develop with the changes in the overall market, I believe that arc welding will neverthe-less remain a key technology in the process of fabricating the structures. Therefore, we plan to keep supplying such products as welding processes and consumables with high efficiency and quality, and promoting effec-tive welding methods for high tensile strength steels and low temperature services, among others.

Overseas, the demand for welding consumables and welding robotic systems is expanding along with the progress of industrialization in emerging nations particularly in Asia. Accordingly, we will conduct the sales and marketing in each region from the nearest Kobelco group base, making sure to respond quickly to each customer’s request and supply quality products and technical supports toward the goal of standing apart from our competitors.

It is our promise to communicate more closely with customers in order to precisely grasp and fulfill their needs to their ultimate satisfaction. Our long overseas experience uniquely positions us to provide the most effec-tive welding products and total welding solutions.

We thank you very much for your continuous patronage to our products and look forward to seeing you in the very near future.

Shinichi TanakaGeneral ManagerInternational Sales & Marketing Sec.Marketing DepartmentWelding BusinessKobe Steel, Ltd.

The XR series stainless steelFCWs help users complywith new OSHA standard

1

3

8

10

9

KOBELCO WELDING TODAYTECHNICAL HIGHLIGHT

Vol. 14 No. 3 2011 3

Suspension member

Rear suspension

Wheel(2 pcs)

Axle beam

MufflerManifold

Frame assy.

Torqueconverter

Trailing arm

Lower arm

Front suspension

Bumper

Radiator

Instrument panelreinforcement

Door impact beam

Seat frame

Axle housing

Shock absorber

Figure 1:MAG and MIG welding applicationsof various car parts

Exhaust system

Because people around the world have been de-

manding that the automobile industry stop polluting the en-vironment and wasting natural resources, in recent years car manufacturers have responded with new engine technologies and lighter auto bodies that improve fuel effi ciency.

The need to reduce auto body weight has led to the application of thinner carbon steels and high tensile strength (HT) steels or light materials such as aluminum alloys as well as to the development of new welding consumables and processes that match the new structural materials. At the same time, car manufacturers have continued to request the welding industry to boost pro-ductivity and efficiency, such as by minimizing the need for repairs and reducing spatter, and thereby cut costs.

This article introduces the up-to-date arc welding processes and consumables for various carbon steels and stainless steels that have been developed by Kobe Steel and applied in automobile manufacturing.

Requirements for arc welding wires for car production

SE (Smooth & Ecology) wires shine in car production

As for welding in car production, arc welding and resistance spot welding are the two most common weld-ing processes. Among various arc welding processes, MAG welding (with CO2, Ar-CO2, or Ar-O2) and MIG welding (with Ar or Ar-O2) are generally used for car production due to their high deposition efficiency and easy automation for robotic welding. These arc welding processes will continue to be favored in car production. Figure 1 shows how these welding processes are applied to car parts. They are especially favored in parts of the undercarriage, the exhaust system and for complicated

shapes where more reliable strength, varied joint con-figuration, and good root-gap tolerance are essential.

Arc welding wires used in car production also must be resistant to burn-through and capable of high speed welding, both of which are quite important for welding very thin plates.

The SE wires for MAG welding, developed by Kobe Steel, feature a special surface treatment instead of a copper (Cu) coating as seen in Figure 2. The SE wire has widely been accepted by car manufacturers as the welding wire that meets their needs.

Table 1 lists the particular SE and Cu-coated wires used for carbon steel welding in the production of vari-ous car parts. Table 2 breaks down the chemical compo-sitions of all weld metals deposited by these wires.

Advanced MAG and MIG Welding Wires :Meeting Car Manufacturing Requirementsfor Fast and Efficient Welding

Advanced MAG and MIG Welding Wires :Meeting Car Manufacturing Requirementsfor Fast and Efficient Welding

KOBELCO WELDING TODAY TECHNICAL HIGHLIGHT

4Vol. 14 No. 3 2011

SE wires are “Smooth” in that they of-fer smooth wire feeding, a smooth arc start, a stable arc, little spatter generation, and a wide welding parameter range due to the special surface treatment that eliminates the need for Cu coating. The benefit of smooth wire feeding allowed by SE-A50 was dem-onstrated by comparing it with a Cu-coated wire at a customer site (see Figure 3); that is, use of SE-A50 resulted in lower consumption of contact tips. In addition, as shown in Fig-ure 4, there were fewer arc start errors with SE-A50 in comparison with a Cu-coated wire that was often suffered from burn-back caus-ing fusion with the contact tip and thus much more arc-start errors.

Figure 2: SE wire (left) and Cu-coated wire (right) differ markedly in appearance.

Table 1: FAMILIARCTM wires for MAG welding of carbon steels in car pro-duction (SE wires in black, Cu-coated wires in red, FCW in green)

Car parts Steel type (Plate thick., mm)

Weldingprocess

Tradedesignation

Wiredia.(mm)

▪Frame assembly▪Arm (lower & upper)▪Axle beam▪Axle housing▪Torque converter

Carbon steel plate(2.3-4.0)

MAG (CO2) SE-50TMG-50T, MG-51T

1.2MAG, MAG-P*1

SE-A50MIX-50SE-A50SMIX-50FSSE-A50FS

▪Axle housing for truck

Carbon steel plate(3.2-6.0) MAG (CO2) MG-50 1.2-1.6

▪Impact beam▪Bumper reinforce-ment

Carbon steel tube & plate (1.4-2.3)


1.2MAG, MAG-P*1

SE-A50MIX-50

▪Suspension member(Cross-member)



1.2MAG, MAG-P*1

SE-A50MIX-50

Galvanized steel plate (1.6-2.6)

MAG (CO2)SE-50TMG-1ZMX-100Z *3

1.2MAG-P*1 SE-A1TSMIX-1TS, MIX-1Z

Corrosion resistantsteel plate1(1.6-2.6) MAG-P*1 SE-A1TS

MIX-1TS

▪Instrument panel reinforcement

▪Seat frame



0.8-1.0MAG SE-A50

MIX-50MAG (CO2), MAG*2 MG-1SP 1.2

▪Body exterior plate▪Pillar reinforcement

Galvanized steel plate (0.6-1.0) MAG*2 MIX-1T 0.6-0.9

*1: MAG-P signifies pulsed MAG. *2: MAG with variable polarity power source.*3: MX-100Z is a metal-type flux-cored wire (FCW).

Table 2: Chemical compositions of all weld metals of FAMILIARCTM wires(SE wires in black, Cu-coated wires in red, FCW in green)

Trade desig.

Shield-ing gas

AWS class.JIS class.*1

Chemical composition (wt%)

C Si Mn P S Ti+ZrSE-50T

CO2

-Z3312 YGW12

0.07 0.49 1.02 0.008 0.016 -MG-50T 0.09 0.44 0.96 0.012 0.012 -

MG-51T A5.18 ER70S-6Z3312 YGW12 0.10 0.88 1.56 0.011 0.012 -

MG-50 A5.18 ER70S-GZ3312 YGW11 0.08 0.51 1.10 0.010 0.010 0.05

MIX-1T

Ar-CO2

-Z3312 G43A2M16 0.06 0.47 0.98 0.010 0.017 -

SE-A50 A5.18 ER70S-GZ3312 YGW16 0.06 0.62 1.27 0.010 0.015 -

MIX-50 A5.18 ER70S-3Z3312 YGW16 0.10 0.55 1.11 0.012 0.011 -

SE-A50S -Z3312 YGW15 0.08 0.35 1.06 0.009 0.011 0.02

MIX-50FSSE-A50FS

-Z3312 G49A0M0 0.04 0.70 1.20 0.010 0.060 -

MG-1Z

CO2

A5.18 ER70S-GZ3312 G49A0C12 0.10 0.49 1.19 0.009 0.009 -

MX-100Z*1A5.20 E71T-1CZ3313 T49J0T15-1CA-U

0.10 0.40 1.55 0.025 0.012 -

SE-A1TSMIX-1TS

Ar-CO2

-Z3312 G49A2M16 0.08 0.60 1.01 0.010 0.006 -

MIX-1Z -Z3312 G43A2M0 0.05 0.18 1.00 0.010 0.004 -

MG-1SP CO2,Ar-CO2

-Z3312 G49A0C11 0.06 0.58 1.32 0.010 0.015 ≥0.04

*1: MX-100Z is a metal-type flux-cored wire (FCW).

78

42

18

7

Cu-coated wire

SE-A50

Shielding gas:80%Ar-20%CO2

Robot-1 Robot-2

Robot-1 Robot-2

Con

sum

ptio

n of

con

tact

tips

(pcs

)pe

r 400

-kg

Arr

ow P

ack

wire

90

80

70

60

50

40

30

20

10

0

Figure 3: On-site survey records about the con-sumption of contact tips in robotic arc welding in comparison between Cu-coated wire and SE-A50.


Vol. 14 No. 3 2011 5

70

10

Cu-coated wire SE-A50

100

80

60

40

20

0

Num

ber o

f arc

sta

rt er

rors

per 5

day

s

Figure 4: On-site survey records about the number of arc start errors in robotic arc welding in comparison between Cu-coated wire and SE-A50

With regard to arc stability, SE wire is also prefer-able to Cu-coated wire. Figure 5 shows how smaller and more stable droplet transfer with SE-A50S was observed by a high-speed camera. Furthermore, with SE wire, a wider range of welding current is applicable. This is because the welding current needed for transition from globular arc to spray arc is significantly lower with SE-A50S than with Cu-coated wire as shown in Figure 6.

0 msec

0 msec

2.2 msec

0.9 msec 1.8 msec

4.4 msec

Cu-coated wire

SE-A50S

Figure 5: Metal droplet transfer profiles taken by a high-speed camera in comparison with Cu-coated wire and SE-A50S (1.2 mmØ, 80%Ar-20%CO2, 260Amp).

0 10 20 30 40

350

300

250

200

150Glo

bula

r-to

-spr

ay a

rc tr

ansi

ton

wel

ding

cur

rent

(A)

CO2 gas ratio in Ar-CO2 gas mixture (%)

Cu-coated wire

SE-A50S

Figure 6: Globular-to-spray arc transition welding current as a function of CO2 ratio in Ar-CO2 shielding gas mixture in com-parison between Cu-coated wire and SE-A50S (1.2 mmØ).

SE wires generate less spatter, as can be seen in the comparison between SE-50T and a Cu-coated wire shown in Figure 7. Larger sizes of spatters by SE-50T are apparently reduced.

Cu-coated wire SE-50T

5

4

3

2

1

0

Spat

ter g

ener

atio

n ra

te (g

/min

)

d < 1.0

d ≥ 1.0

d: Spatter particle dia. (mm)

Figure 7: Comparison of spatter generation rates between Cu-coated wire and SE-50T (1.2 mmØ, CO2, 240 Amp)

In terms of corrosion resistance, SE wire also per-forms well. Figure 8 shows that corrosion resistance of SE wire is equal to or better than Cu-coated wire after 10% NaCl solution was sprayed on the wire surfaces and left in an atmosphere of 30°C × 80% RH (Relative Humidity) for two hours.

Cu-coated wireSE wire

Figure 8:SE wire exhibits excellent corrosion resistance in an accelerated corrosion test (10%NaCl solution spray,

30°C×80%RH, 2 hrs) in com-parison with Cu-coated wire

“Ecology” in SE wires relates to the elimination of the Cu coating and the toxic fumes that accompany its use. As seen in Figure 9, SE wire is lower than Cu-coated wire in solid waste, CO2 emissions and energy consumption, which factor highly in life cycle assess-ment (LCA).

Cu-coated wire 1

0.8

0.6

0.4

0.2

0

SE wire

Solid waste CO2 gas Energy

LCA

eva

luat

ion

(Cu-

coat

ed w

ire: 1

)

Figure 9: LCA evaluation of Cu-coated wire and SE wire

SE wire emission of Cu fume is almost zero as shown in Figure 10. It also contributes to achieving a Cu fume PEL (Permissible Exposure Level) of 0.1 mg/m3 as per the OSHA (Occupational Safety and Health Adminis-tration) standards.

200 250 300 350

6

5

4

3

2

1

0

Cu-

fum

e em

issi

on ra

te

(mg/

min

)

Cu-coated wire

SE-A50S

Welding current (A)

Figure 10:Cu-fume emission rates of Cu-coated

wire and SE-A50S

KOBELCO WELDING TODAY TECHNICAL HIGHLIGHT

6Vol. 14 No. 3 2011

MIX-1T (0.6 mmØ) + variable polarity power sourceA variable polarity power source, which makes it

easy to change the ratio of electrode positive polarity (EP) and electrode negative polarity (EN), is useful for controlling the penetration and wire melting rate in every weld passes. Ultra-thin plates, such as the 0.6-0.7 mm plates used for car bodies, have generally been spot welded. However, to fulfill recent requirements for increased car body rigidity, arc welding is preferred to use in the place of resistance spot welding.

Figure 15 shows the test results of MIX-1T (0.6 mmØ) in robotic short-bead welding on 0.7-mm thick plates with a 0.5-mm root gap at three different EP-EN ratios. 100%EP resulted in burn-through; 27%EP-73%EN caused a too narrow bead, and the best result was ob-tained with 53%EP-47%EN, which has already been ap-plied by one of the biggest Japanese car manufacturers.

Figure 15: EP:EN polarity ratio of 53:47 resulted in the best bead contour in short-bead welding with MIX-1T of 0.6mmØ (Plate thick.: 0.7 mm; Shielding gas: 80%Ar-20%CO2; Weld-ing parameters: 60A-16V-50cm/min)

MIX-1T (1.2 mmØ) with pulsed MAG (Ar-5%O2)In thin plate welding, conventional MAG processes

require to use a small-diameter wire of 0.9-1.0 mm with low welding currents and speeds to prevent burn-through at the cost of welding efficiency. A new process that combines MIX-1T (1.2 mmØ) and pulsed MAG (Ar-5%O2 shielding gas) has made it possible to weld a 1.4-mm thick plate joint with a 2-mm root gap at speeds as fast as 100 cm/min as shown in Figure 14.

Figure 14: Pulsed MAG (Ar-5%CO2) with MIX-1T outstrips con-ventional MAG processes in root-gap tolerance.

The most stringent requirement of car manufacturers is for welding of the highest efficiency without stop-pages. High welding speeds of 90-140 cm/min without any welding defect are required; slag generation must also be reduced as slag causes paint to peel off after painting. In order to meet these requirements, SE-A50FS has been developed; also, as its sister product, the Cu-coated MIX-50FS has been marketed. These two wires are called FS wires. The advantages of FS wires over conventional wires are discussed below.

Welding direction

Humping bead Horizontallap weldingat a speed of140 cm/min

Plate thick: 2.9 mm

Conventional wire

MIX-50FS or SE-A50FS

Good bead contour in high speed weldingFS wire exhibits good bead contour without hump-

ing and undercut whereas conventional wire results in humped bead, undercut and convex bead ― Figure 11.

Figure 11: MIX-50FS or SE-A50FS excels in bead contour over conventional wire in high speed welding on thin plate joints.

Little slag generation and easy slag removalWhereas slag associated with the FS wire is con-

densed in one spot, thus easier to remove, but the slag of the conventional wire is scattered along the entire length of bead ― Figure 12.

MIX-50FS

Conventional wire

Condensed slag

Scattered slag

Figure 12: A condensed slag spot with MIX-50FS is easier to remove over scattered slag with conventional wire.

Figure 13: A comparison of cross sectional bead shape be-tween SE-A50FS and conventional wire.

SE-A50FS Conventional wire

More tolerable to deviated wire-trackingFS wires offer flat, wide bead shape, which enables

to tolerate when wire-tracking deviates from a weld line ― Figure 13.

(Not weldable)

Plate thick.: 1.4 mm; Welding speed: 100 cm/min

Root gap

3

2

1

0

Tole

rabl

e ro

ot g

ap (m

m)

New MAGAr-5%O2

Pulsed p.s.

Conv. MAGAr+20%CO2Inverter p.s.

Conv. MAGAr+20%CO2Pulsed p.s.

Conv. MAGCO2

Inverter p.s.

Solid wireJIS YGW12

Solid wireJIS YGW16 Solid wire

JIS YGW17

MIX-1T

EP:EN = 100:0 EP:EN = 53:47 EP:EN = 27:73

Development of SE-A50FS and MIX-50FS, exclusive wires for car production

Unique MAG processes with dedicated wires for specific applications


Vol. 14 No. 3 2011 7

Only-One

SE-A1TS or MIX-1TS with pulsed MAG The welding of underbody parts such as car sus-

pensions, where galvanized steel plates are often used to prevent corrosion, requires special care to reduce the spatter and porosity caused by the zinc coating on the surface. Although non-surface-treated corrosion-resistant steel plate has increasingly been adopted for such parts, it often sustains solidification cracks dur-ing welding due to the alloying elements of copper and phosphorous contained in the steel plate.

Pulsed MAG with SE-A1TS or MIX-1TS can solve these problems. As shown in Figure 16, pulsed MAG with MIX-1TS offers better bead appearance as opposed to MAG (CO2) welding with conventional wire on a galva-nized steel plate. Figure 17 shows the positive influence of MIX-1TS with two types of shielding gases against so-lidification cracks on the corrosion-resistant steel plate.

Figure 16: In galvanized plate welding, pulsed MAG with MIX-1TS results in a good bead look without spatter adhesion (right) whereas MAG (CO2) welding with conventional wire exhibits much spatter particles adhered and porosity (left).

Corrosionresistant steel

Weld nuggetL

a b

Groove gap:1.6 mm

Crack

Crack ratio (%) = (a+b)/L x 100

Conv. wireMIX-1TS

Ar-5%O2

Ar-4%O2-20%CO2

11

13

0 0

15

10

5

0

Cra

ck ra

tio (%

)

Arc Spot Crack Test

Figure 17: MIX-1TS outstrips conventional wire in solidification crack resistance on corrosion-resistant steel plate.

MAG welding wires for HT steelsOne way to reduce car body weight is to apply HT

steels with thinner plates. Use of HT steels had been limited to those parts not requiring fatigue strength, such as the bumper, seat frame, instrument panel, and impact members. However, more recently the undercar-riage can also be reduced in weight with the application of advanced HT steels of 590, 780 and 980 MPa classes to such parts as the arm, beam, frame and suspensions.

In order for welding wires to meet the requirements of tensile strength and fatigue strength, the MX-MIG process that uses TRUSTARCTM MM-1HS metal-type flux-cored wire has been developed. The process is de-scribed in more detail on of this issue.

Welding wires for exhaust systemsIn car exhaust systems, stainless steel sheets and

pipes are applied to exhaust manifolds, converters and mufflers. Because such parts are assembled with thin pipes and press-formed shapes of a wall thickness of 0.8-2.0 mm, the welding joints necessarily contain small or large root gaps. This is why burn-through resistance and root-gap bridging ability are primary concerns for welding wires. Table 3 shows the recommended weld-ing wires for such applications and the chemical com-positions of respective all-deposited metals.

Table 3: PREMIARCTM wires (1.2 mmØ) for stainless steel and the chemical compositions of all-deposited metals

Trade desig.*1 MX-A430M MG-S430M MG-S430NbS MG-S308

AWS class. - - - A5.9 ER308Applicable stainless steel grade

Ferritic Austenitic

430, 409, 410L, 444 304

Weldingprocess

MAG(80%Ar-20%CO2)

Pulse MIG(98%Ar-2%O2)



C (wt%) 0.05 0.02 0.02 0.05Si 0.40 0.90 0.88 0.45Mn 0.14 0.40 0.29 1.64P 0.008 0.021 0.023 0.024S 0.017 0.002 0.001 0.002Cr 17.0 18.4 18.1 20.0Ni - 0.23 0.21 9.8Nb 0.75 - 0.56 -

*1: MX- is for metal-type flux-core wire whereas MG- is for solid wire.

MX-A430M metal-type flux-cored wire is excellent in burn-through resistance as seen in Figure 18 and in root-gap bridging ability as shown in Figure 19.

ConventionalER430 wire

MX-A430M

No burn-through

No burn-through

0 100 120 140 160 180 200 220

120

100

80

60

40

0

Welding current (A)

Wel

ding

spe

ed (c

m/m

in)

Wire dia.: 1.2 mmØShielding gas: 80%Ar-20%CO2Plate thick.: 2.0 mm

Figure 18:MX-A430M offers a wider current-speed range over conventional ER430 wire to prevent burn-through.

MX-A430M Conv. ER430 solid wire

Figure 19: MX-A430M offers better root-gap bridging ability and smoother fusion over conventional ER430 solid wire.

References:[1] Kobe Steel Welding Technical Reports, Vol. 40 2000-4, -12[2] Kobe Steel Welding Technical Report, Vol. 46 2006-11 [3] Kobe Steel Engineering Report, Vol. 52

MAG (CO2) with conv. wire Pulsed MAG with MIX-1TS

KOBELCO WELDING TODAY BULLETIN

8Vol. 14 No. 3 2011

An Innovative Metal-Type Flux Cored Wirefor the MX-MIG Welding Processthat Improves Fatigue Strength

and Corrosion Resistance

MM-1HSMM-1HS

The newly developed MX-MIG welding process com-bines MM-1HS (a metal-type f lux cored wire with

unique chemistry fl ux), pure-Ar shielding, and pulsed-arc welding power source. It remarkably improves the fatigue strength of the welded joint by means of the following hybrid effects. This innovative technology will enable HT steel to be applied more extensively to car body compo-nents, thereby contributing to the auto body weight reduc-tion.

The hybrid effects of the MX-MIG process consist of lower stress concentration at the weld toe with a larger f lank angle (Figure 1) and of improved residual stress distribution in the weld (Figure 2), when compared with conventional solid wire MAG. The MX-MIG process also offers flat and wide bead shape as shown in Figure 3.

ρ

5 mm5 mm80%Ar+20%CO2Solid wire & MM-1HS &

100%Ar

Figure 1: MX-MIG with MM-1HS offers a larger flank angle weld toe as compared with conventional solid wire MAG.

Figure 3: MX-MIG with MM-1HS features flat and wide bead contour with slag-less shiny surface on a lap joint.

104 105 106 107 1080

100

200

300

400

500

Plane plate

Fatigue limit strength: 1.6 times

Rupture time at 350MPa: 6.2 times

Conv. solid wire MAG

Am

plitu

de s

tress

(S) (

MP

a)

Number of stress cycles (N)

MM-1HS

Figure 4: MX-MIG with MM-1HS outstrips conventional solid wire MAG in lap joint fatigue strength.

MX-MIG welded joint exhibits higher fatigue strength, reaching closer to plain steel plate, over conventional MAG in the fatigue test with lap-fillet weld joints of 780MPa class HT steel plates of 3.4-mm thick (Figure 4).

Car bodies are required to be corrosion resistible in the usage environment particularly in road-salting regions. For this, car underbodies are electro deposition coated after welding. To assess the coating quality and corrosion resistance of MM-1HS weld, cyclic corrosion test (CCT), an accelerated corrosion test, was conducted on electro deposition coated weld joints. As shown in Figure 5, slag-less MX-MIG weld exhibits a uniform coating and thus better corrosion resistance, whereas conventional MAG weld's coating is partly peeled off along the toe because of detachment of slag after the coating and thus much rust is generated along the weld.

Only-One

Conv. solid wire MAG MX-MIG

Uncoated area

Much rustMuch rust Little rustLittle rust

Uniform coating

Figure 5: Electro deposition coated bead appearances (top) and CCT results (bottom) highlight the excellence of MX-MIG with MM-1HS over conventional solid wire MAG.

In addition, the MX-MIG process offers little spatter (Figure 6) and prevents hump formation in high speed welding (Figure 7).

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0

>1

<0.5

)nim/g( rettaps fo tnuo

mA

MM-1HS

Conv. MAG

Spatter particle size (mmØ)

0.5-1Figure 6:

MX-MIG with MM-1HS mark-edly reduces larger size par-ticle spatter as compared to

conventional solid wire MAG.

Humping

Conv. MAG

MX-MIG

Figure 7:MX-MIG excels in high-speed

welding due to low tendency of humping(1.2Ø, 350Amp, 140cm/min, 20-deg upward).

Comp. Tension Comp. TensionConventionalsolid wireMAG MM-1HS

Residualstress (MPa)

Residualstress (MPa)

Figure 2: MX-MIG with MM-1HS is characterized by larger compression stress at weld toe vs. conv. solid wire MAG

KOBELCO WELDING TODAYBULLETIN

Vol. 14 No. 3 2011 9

Kobelco Welding India ... a strategic base for sales and marketing with the potential for sourcing important raw materials

In June 2011, Kobelco Welding India Pvt. Ltd. (KWI) was established in Gurgaon, Haryana state, about

30 km southwest of New Delhi. The new company is formed under a joint investment between Kobe Steel, Ltd., Kobe Welding (Singapore) Pte. Ltd. and Taseto Co., Ltd.

Commencing operations with five staff members, in-cluding two Japanese, the company will focus on sales and marketing of welding consumables as well as sales support and maintenance services of welding robotic systems.

In India, growing demand for welding consumables offers great potential for Kobe Steel. In particular, rapid expansion in the construction of new power plants is likely to increase demand for high value-added weld-ing products, one of Kobe Steel’s strengths. In addition, with Japanese firms in such fields as heavy electrical machinery, construction equipment and automobiles increasing their presence in India, the need to build a support framework for not only welding consumables but also welding robotic systems is becoming urgent.

In addition to marketing, KWI is expected to strengthen the cost competitiveness of the Kobelco welding group companies by searching for and procur-ing raw materials for welding consumables, since India is expected to become an important source of these ma-terials.

KWI is thus positioned as an Indian base of strategic operations that will enhance marketing effectiveness in coordination with operations in Southeast Asia.

Posing at the office entrance are staff mem-bers of KWI and Shinichi Tanaka, GM of ISMS, Welding Business, KSL (the 1st from the left)

Kobelco Welding Marketing of Korea ... expanding marketing networks in the energy field

KSL has been steadily increasing sales of welding consumables in South Korea through McQAN, a dis-tributor. In 1995, when KSL established KWK, which produces and markets flux cored wires (FCWs) for mild steel, it was unable to take full ownership of the unit. Through the cooperation and support of McQAN, how-ever, KSL has been able to solidify and expand KWK’s business, especially the marketing of FCWs to Korean shipbuilders. As far as welding consumables for LNG tanks and other energy fields are concerned, these have been exported from Japan and distributed by McQAN.

Anticipating that demand will decline in the Korean shipbuilding industry in the future, KWMK aims to maintain sales volume by offering welding solutions that combine on-site response and technical develop-ment capabilities with welding consumables, construc-tion methods and welding equipment.

In the energy field, Korean heavy manufacturers are active in overseas emerging markets, where they are seeking orders in energy plant construction. KWMK aims to build an efficient marketing network throughout South Korea, strengthening ties with these major cus-tomers and securing large sales volumes.

In April 2011, Kobelco Welding Marketing of Korea Co., Ltd. (KWMK) was established in Pusan, South

Korea, as a joint venture between Kobe Steel, Ltd. (KSL), Kobe Welding of Korea Co., Ltd. (KWK), Shin-sho Corporation and McQAN Corporation (McQAN). It started the marketing of welding consumables in Sep-tember 2011.

Staff members of KWMK poses at the entrance of KWMK office in Pusan, South Korea.

KOBELCO WELDING TODAY BULLETIN

10Vol. 14 No. 3 2011

In front of the Saturn Rocket at the NASA Johnson Space Center the author, Ryusaku (Ray) Yanagimoto, National Marketing Manager, KWAI poses with his daughter on his shoulder.

My dearest KWT readers! I am Ryusaku (Ray) Yanagimoto and I was assigned to Kobelco

Welding of America Inc. (KWAI) as National Mar-keting Manager in April 2011.

Kobe Steel, KWAI’s parent company, usually supplies its customers with the welding products they need from the nearest sales and production center. These are located in many countries, includ-ing Japan, Korea, China, Thailand, and Singapore in Asia and the Netherlands in Europe.

In the USA, however, KWAI was established in Houston, Texas in 1990 to serve as the base for marketing and sales to the North American market. Last year, in 2010, we celebrated our twentieth year of serving our customers!

I believe there are two key factors behind KWAI’s success in marketing and sales. One is that we have been blessed with talented and loyal staff members, while the other is that our main product, flux cored wires (FCWs) for stainless steels, is re-puted by many customers for “QTQ,” which stands for Quality Products, Technical Supports and Quick Delivery, the Kobelco welding group slogan.

KWAI’s products are market leaders in North America. As a matter of fact, KWAI was awarded the “North American Stainless Steel Tubular Wire Excellence in Product Line Leadership of the Year Award” by the internationally renowned research company Frost & Sullivan in 2008.

In the recent years, not only has KWAI been operating in North America but also expanding

into Central and South America where a number of quite large energy-related projects are in progress. We plan to respond to all new inquiries by offering the same quick delivery and systematic technical support that all our customers have come to expect.

Meanwhile, after arriving at my new post and helping my family get set up in Houston, I took my family to visit NASA’s Johnson Space Center, one of the important bases for space exploration in the USA and located in a nearby suburb. It is well known that through this center, Captain Armstrong, the first man to walk on the Moon, delivered his fa-mous message: “That’s one small step for man, but one giant leap for mankind.”

When I saw the real, full-scale space shuttle and other rockets there, their enormous scale was over-whelming. And I could also feel that I, too, shared the enthusiastic passion of the people who dreamed of the challenge of flying into the unknown.

I sincerely hope that the KWT readers can visit this exciting “Space City” of Houston and feel the same passion as I did. And if you do, please visit KWAI as well to meet our excellent staff members.

I truly look forward to seeing you in the nearest future.

From its location in the exciting Space City of Houston, KWAI expands to Central and South America

KWAI’s talented and loyal members, posing at the office lobby (the 1st from the right in the 2nd row is the author)

GLOBAL MANUFACTURING ANDSALES BASES

EUROPE

AMERICA

ASIA

JAPAN:KOBE STEEL, LTD., Welding BusinessMarketing Dept., International Sales & Marketing Sec.Tel. (81) 3 5739 6331 Fax. (81) 3 5739 6960

KOREA:KOBE WELDING OF KOREA CO., LTD.Tel. (82) 55 292 6886 Fax. (82) 55 292 7786

KOBELCO WELDING MARKETING OF KOREA., LTD.Tel. (82) 51 329 8950 to 8952 Fax. (82) 51 329 8949

CHINA:KOBE WELDING OF SHANGHAI CO., LTD.Tel. (86) 21 6191 7850 Fax. (86) 21 6191 7851

KOBE WELDING OF TANGSHAN CO., LTD.Tel. (86) 315 385 2806 Fax. (86) 315 385 2829

KOBE WELDING OF QINGDAO CO., LTD.Tel. (86) 532 8098 5005 Fax. (86) 532 8098 5008

SINGAPORE:KOBE WELDING (SINGAPORE) PTE. LTD.Tel. (65) 6268 2711 Fax. (65) 6264 1751

THAILAND:THAI-KOBE WELDING CO., LTD.Tel. (66) 2 324 0588 to 0591 Fax. (66) 2 324 0797

KOBE MIG WIRE (THAILAND) CO., LTD.Tel. (66) 2 324 0588 to 0591 Fax. (66) 2 324 0797

MALAYSIA:KOBE WELDING (MALAYSIA) SDN. BHD.Tel. (60) 4 3905792 Fax. (60) 4 3905827

INDONESIA:P.T. INTAN PERTIWI INDUSTRI(Technical Collaborated Company)Tel. (62) 21 639 2608 Fax. (62) 21 649 6081

INDIA:KOBELCO WELDING INDIA PVT. LTD.Tel. (91) 124 4010063 Fax. (91) 124 4010068

USA:KOBELCO WELDING OF AMERICA INC.Tel. (1) 281 240 5600 Fax. (1) 281 240 5625

NETHERLANDS:KOBELCO WELDING OF EUROPE B.V.Tel. (31) 45 547 1111 Fax. (31) 45 547 1100

kwt 14-3 rev1

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